Tuesday, June 17, 2014

The term “Stick Welding” refers to the stick-like appearance of thin
cylindrical rods employed in the most common and widely used form of Shielded
Gas Arc Welding – Stick Welding.Consumable electrode rods come in varying diameters and lengths, and consist
of:

A wire core (usually steel)
which provides the filler metal that bond with the base metal

A flux coating surrounding
the filler metal, that transitions into a shielding gas (when
super-heating by welding machine generated electrical current) to protect
the weld from impurities naturally present in the air that can potentially
create inclusions and porosity.

Understanding the American Welding Society’s (AWS) Electrode Rod
Numbering System

Welding project elements such as the thickness of the base metal, length of
the weld, position of the weld (flat, vertical, overhead, etc…) and direction
of travel, are all factors that determine the type of consumable electrode rod
a particular welding project requires.

Electrode Classification

An electrode’s classification, defined by a four digit number (based on a
numbering system created by the AWS), addresses the factors outlined above, and
indicates the type of electrode best suited to a specific welding project.The classification number defines electrode properties such as:

Tensile strength

Direction of travel

Composition (of the shielding
gas)

Penetration

Type of electrical current

Therefore, if you’re welding a thicker base metal, on a workbench in a
welding shop, with an AC powered welder – you need an electrode with a high
tensile strength capable of reaching deep penetration, which travels
horizontally and can be charged by Alternating Current.

The Four Digit Numbering System

The following examples illustrate the numbering system’s basic application:Example #1 - Electrode Number 6010 The first two digits – 60 – refers to the tensile strength
of the filler metal in thousands of pounds, i.e. 60 thousand pound tensile
strengthThe third digit – 1 – refers to the direction of travel,
i.e. this electrode is multi-directional, and can be used to weld material in a
horizontal (flat), vertical (straight-up-and-down) or upside down (overhead)
position.The fourth digit – 0 – refers to three separate elements:

Composition of the flux
coating: 0 = cellulose and sodium

Depth of penetration: 0 =
deep penetration

Type of electrical current
used to charge the electrode: 0 = DC (Direct Current).

Example #2 - Electrode Number 7018 The first two digits – 70 – refers to the tensile strength
of the filler metal in thousands of pounds, i.e. 70 thousand pounds tensile
strengthThe third digit – 1 – refers to the direction of travel,
i.e. this electrode is multi-directional, and can be used to weld material in a
horizontal (flat), vertical (straight-up-and-down) or upside down (overhead)
position.The fourth digit – 8 – refers to three elements:

Composition of the flux
coating: 8 = cellulose and potassium

Depth of penetration: 8 =
deep penetration

Type of electrical current
used to charge the electrode: 8 = AC (Alternating Current).

Additional Classification

Some electrodes are classified by five or six digits, for example: E7018-XThe “E” indicates the rod is an “electrode.”The “X” refers to additional classifications.Let’s say an electrode is classified as: E7018-1The “1” refers to additional impact strength, which yields a sturdier more
robust weld.Another example would be: E7018-MThe “M” refers to military grade standards for increased strength, indicates
the electrode is stored in a low moisture environment, and produces less
hydrogen when expended in the welding process.